FILO --> zelf format to reduce size to 32k below.

Eric,
Can you add something in filo Makefile and make it produce zelf format?
If the size to be 32k below, for fallback boot the payload could be
FILO+Etherboot --> [384k, 416k](FILO) + [416k, 448k) (Etherboot) , instead
of putting the Etherboot in the [0,64k) of ROM, and FILO in the [384k,
448k).
Regards
YH